"""Slot domain data classes (REQ-001, REQ-002)."""
from __future__ import annotations

from dataclasses import dataclass, field
from datetime import date, datetime
from decimal import Decimal
from typing import Optional
from uuid import UUID

from trex_core.domain.slot.state import SlotState


@dataclass
class Slot:
    """Single daily_slot row.

    Matches the slot column contract recorded in dcy-001 부록 A and
    docs/data-model.md (trex-core stores this in-memory for now; a future
    persistence layer must satisfy the same contract).
    """

    slot_id: UUID
    trading_date: date
    status: SlotState
    symbol: Optional[str] = None
    qty: Optional[float] = None
    avg_price: Optional[float] = None
    # dcy-012 / REQ-002: side-agnostic "current pending order limit price"
    # (renamed from entry_price). Set on pending entry (buy/sell limit), cleared
    # on pending exit (→HOLDING, →CLOSED) so a buy limit never leaks into a sell
    # order (issue #10). None => market order at dispatch.
    limit_price: Optional[float] = None
    allocated_capital: Optional[float] = None
    order_id: Optional[str] = None
    strategy_id: Optional[str] = None
    broker_order_id: Optional[str] = None  # BAT-003 / REQ-011 (trex-orbit lineage)
    portfolio_id: Optional[str] = None  # BAT-006 / REQ-025 (trex-orbit lineage)
    sell_strategy_id: Optional[str] = None  # BAT-008 / REQ-047 (trex-orbit lineage)
    forced_close_at: Optional[datetime] = None  # BAT-014 / REQ-066 (trex-orbit lineage)
    stop_loss_price: Optional[Decimal] = None   # REQ-035 / BAT-010
    take_profit_price: Optional[Decimal] = None  # REQ-035 / BAT-010
    # dcy-019 / REQ-002 (BAT-025): slot-scoped cumulative entry count. +1 on each
    # allocation transition (idle/closed → pending_buy); drives admission slot
    # selection (lowest entry_count first). Distinct from the symbol-scoped
    # daily_symbol_entries counter (REQ-002 AC-3) — different key/purpose.
    entry_count: int = 0
    created_at: Optional[datetime] = None
    updated_at: Optional[datetime] = None


# Canonical column contract for `Slot` (dcy-001 OQ-2 / FR-5).
# test_contract.py asserts this matches `dataclasses.fields(Slot)` so any
# field add/remove fails loudly. Type mapping lives in the docs (dcy-001 부록 A
# / docs/data-model.md), not here — names/presence only.
EXPECTED_SLOT_FIELDS: frozenset[str] = frozenset({
    "slot_id",
    "trading_date",
    "status",
    "symbol",
    "qty",
    "avg_price",
    "limit_price",
    "allocated_capital",
    "order_id",
    "strategy_id",
    "broker_order_id",
    "portfolio_id",
    "sell_strategy_id",
    "forced_close_at",
    "stop_loss_price",    # REQ-035
    "take_profit_price",  # REQ-035
    "entry_count",        # dcy-019 / REQ-002 (BAT-025)
    "created_at",
    "updated_at",
})


@dataclass(frozen=True)
class SlotCapacity:
    """Snapshot of slot capacity returned by compute_slot_capacity (REQ-002 AC-6)."""

    idle_count: int
    holding_count: int
    pending_count: int
    total_slots: int
    scarcity_ratio: float


@dataclass(frozen=True)
class SlotTransitionRecord:
    """One append-only row in slot_transition_log (REQ-001, REQ-002)."""

    slot_id: UUID
    from_state: SlotState
    to_state: SlotState
    ts: datetime
    reason: str
    actor: str
    extra: dict = field(default_factory=dict)